Uganda Journal of Agricultural Sciences

Effect of Phosphorus-Based Fertilizer on Groundnut Yield and Incidence of Groundnut Rosette Disease in West Nile Region of Uganda

Alex Abaca, John Walakira, Odama Emmanuel, Komakech Alfred, Sadik Kassim — Wed, 15 Sep 2021 00:00:00 +0000

The objective of this study was to establish the effects of Di-ammonium phosphate (DAP) fertilizer micro-dosing on yields and the incidence of groundnut rosette disease (GRD) on five groundnut varieties in West Nile region of Uganda. The field experimental design used in this study was 5x2 factorial laid in a randomized complete block design (RCBD) with three replicates per location across 6 locations. The results indicated that there were significant (p = 0.05) differences in groundnuts yields across locations and varieties (0.554 – 1.742 tons per hectare) with or without micro-dosing with DAP fertilizer. The effects of DAP fertilizer micro-dosing in groundnut production were twofold: increase in yields across locations from 427.27kg/acre with no micro-dosing to 525.73kg/acre with micro-dosing (23.04% increment) and varieties from 420.46kg/acre with no micro-dosing to 529.71kg/acre with micro-dosing (13.77% increment); and a reduction of groundnut
rosette virus disease incidence across locations from 15.13% with no micro-dosing to 11.20 with micro-dosing (27.76% reduction) and on varieties from 15.08% with no micro-dosing to 11.82% with micro-dosing (34.62% reduction). This is the first report of a prospective DAP fertilizer micro-dosing alongside other improved agronomic practices which can be integrated fully into groundnut production in West Nile region of Uganda. To manage yields and GRD incidences, micro-dosing of
crops should be taken as a climate smart technology as identified by Food and Agricultural Organization.

Coffee Berry Moth, Prophantis smaragdina (Butler) (Lepidoptera: Pyralidae): Another threat to Robusta coffee, Coffea canephora production in Uganda

Wed, 15 Sep 2021 00:00:00 +0000

A structured questionnaire eliciting farmers’ knowledge of Coffee Berry Moth (CBM) was administered to 10 coffee farmers selected in the villages surrounding Kaweri. Additionally, 10 coffee trees were assessed for CBM infestation in farmers’ gardens and at Kaweri. Half of the farmers knew CBM and >50% of them first observed it on their coffee recently. However, 42.8% of them thought CBM causes no effect on coffee yields. Furthermore, 57.2% of them could identify the pest by the
characteristic silk webs and the same percentage was aware that CBM causes more damage during the dry season. Majority (71.2%) of them did not know the effect of shade on its infestation while all of them were not aware of any alternative host for it. Lastly, only 14.2% of the farmers mentioned that they were managing CBM. At plot level, CBM was observed in all the Kaweri sections and farmers’ gardens assessed and the infestation was significantly (p≤0.05) higher at Kaweri than in
farmers’ gardens. Infestation decreased significantly (p≤0.05) with increase in pruning and intercropping. The results showed that CBM is gaining economic importance as a pest of Robusta coffee in Uganda. However, limited farmers’ knowledge about its management, coupled with scanty literature, points to urgent need for research towards developing integrated management strategies for it.

Effect of Spent Mushroom Substrate and NPK Fertilizer on White and Orange-Fleshed Sweet Potato Varieties in South Eastern Nigeria

Ogbologwung L.P., Okpara D.A., Adedokun O. M. — Wed, 15 Sep 2021 00:00:00 +0000

Spent mushroom substrate (SMS) and NPK (15:15:15) fertilizer were assessed under field conditions for their comparative effects on white and orange-fleshed sweet potato varieties in Umuahia southeastern Nigeria. The experiment was a split-split plot in randomized complete block design with three replicates. The main plot treatments were two sweet potato varieties (white-fleshed TIS87/0087 and orange-fleshed Umuspo 3). The split plot treatments were five NPK fertilizer rates (0, 100, 200, 300 and 400kg/ha) while the split-split plot treatments were three SMS levels (0, 2 and 4t/ha). Averaged across sweet potato varieties and NPK fertilizer, SMS significantly increased leaf area index, shoot biomass and storage root yield. Application of NPK fertilizer increased leaf area index and shoot biomass in both years and storage root yield in 2019. The white-fleshed TIS87/0087 variety produced significantly higher shoot biomass than Umuspo 3 in both years. TIS87/0087 had higher root yield than Umuspo 3 in 2018, but in 2019, the latter out yielded the former. Three-way interactions were significant for shoot biomass in 2018 and for storage root yield in both years. The highest shoot biomass (28.70 – 30.0t/ha) in 2018 was obtained from TIS87/0087 at moderate rates of
2t/ha SMS and 300kg/ha NPK fertilizer and from Umuspo 3 at 2t/ha SMS and 200kg/ha NPK fertilizer. The highest storage root yield 30.0t/ha was obtained from TIS87/0087 at 4t/ha SMS alone in 2018 and 37.1t/ha yield from Umuspo 3 at 4t/ha SMS only in 2019. The results showed that 4t/ha SMS was sufficient to promote high root yields in sweet potato in the area.

NIRS Predictions, Phenotypic Variability and Optimization of Cooking Time for Evaluation of the Root Softness of Boiled Cassava

Wed, 15 Sep 2021 00:00:00 +0000

This study aimed at quantifying the extent of genetic variability of softness in cassava germplasm across varied cooking times and root sections. It also examined the possibility of using Near Infrared Spectroscopy (NIRS) for measurement of cassava root softness. Softness was evaluated using a penetrometer. This was done at 15, 30 and 45minutes cooking time, all across proximal, middle and distal root sections. These measurements were done on 57 accessions. For each sample, spectra were acquired using NIRS Benchtop (FOSS DS2500) on a composite of each root section of mashed fresh cassava sample. Modified Partial Least Squares regression (MPLS) was used for NIRS calibration development using WINISI software. Significant (P < 0.001) variability in softness was established. Cooking time significantly influenced softness and there were significant accession and root part interaction (P < 0.001). Wide variability and high heritability (H = 0.8) were found for softness at 30 minutes cooking time. Highest association was found with 30- and 45-minutes cooking time (r = 0.58). Strong association was observed between middle root section with distal (r = 0.74)
and proximal (r = 0.73). NIRS softness calibration (R2c) were 0.445, 0.413 and 0.521 for 15-, 30-, and 45-minutes cooking time respectively. NIRS prediction (R2p) were 0.322, 0.192, and 0.390 for 15-, 30-, and 45-minutes cooking time respectively. These results suggest that 30 minutes cooking time and middle root section are optimum for softness phenotyping.

Situation of ticks and seroprevalence of Theileria parva in two farming systems in Nakaseke and Nakasongola districts of Uganda

Kwesiga S., Okello-Onen J., Ogwal Byenek S., Otim-Nape W. — Wed, 15 Sep 2021 00:00:00 +0000

This study delved into the composition of ticks, prevalence of Theileria parva and management of East Coast Fever in Nakaseke and Nakasongola districts of Uganda. The tick challenge on animals was assessed and whole blood was collected for determination of seroprevalence of Theileria parva using Enzyme-Linked Immunosorbent Assay. Majority (82.3 percent) of the cattle were found to be infested with Rhipicephalus appendiculatus (88.2 percent), Ambryomma variegatum (7.5 percent) and Rhipicephalus evertsi (4.3 percent). Majority (80.7 percent) of the respondents believed that tick infestation was severe and regularly managed using acaricides (65.3 percent). In the pastoral farming system, no ticks were found on calves below 6 months of age. In the mixed crop-livestock farming system, all cattle age groups were exposed to the ticks. The seroprevalence of T. parva varied among age groups of cattle in both farming systems. There was moderate correlation between the mean number of R. appendiculatus ticks and seroprevalence of T. parva (r = 0.47). Association was established between mean number of ticks and farming system (p = 0.019) and percentage positivity of T. parva and farming system (p = 0.007). Theileria parva was prevalent in the two farming systems despite frequent application of acaricides. Thus, the study provides evidence of the tick-borne disease pathogens and vectors responsible for ECF, R. appendiculatus being the principal tick species infesting cattle in the area. Creation of community-based technical and advisory services for livestock health management is recommended.